Dynamo-electric machine.



S. R. BERGMAN.

DYNAMO ELECTRIC MACHINE.

APPLICATION FILED MAYI3.19HL

Patented May14,1918.

Inventor gman.

I J tb' e B R n e V S UNITED STATES PATENT OFFICE.

emu. nfinamm, 0F emblem, mhsemnesmws, wsemiwon T0 GENERAL mac-mic mam, e eoeronmqow we we: YGRR. m nute-firmware mmn'mn 's eeificemon owetereratent.

Patented May 14, 1918.

To all wkom it may concm:

My invention relates to dynamo-eleflfic nleeh'i'nes ancl part-iculaflkr to cdmpe isated diredt eurrelflt dj'i'le'mib-elefiie mhe'hihe'e. M dre especially the invention relates to u (ii -eel: chi-rent (El *fifihl-QTBCiI'lC meplgheheving a cl'lstri'but compensatfihg will ifig and n is'tiihu'ted exciting wifidin" fihd hiya ticular "to 'a compensated lreet eui'renu dynamo-'el'ecti'ic machine 015 the hype HES- cldsed in my U. s. Le'tiex s Patent Ne. 1,173,090, patented Feb. 22, 191e, r I

The i nveh tien lee ior its ebjects lie i30- vide en imjfi'fvefl dynafnb 'elbti'ie Iiibihe havih' a hbvel field megrree 'st detqi e ior al distri uted field winding, and t6 provide an improved 'rrimgerhent ()1 'ekeitihlg' Wi'li dir ''s fer a diIect burreht dj h-meecftric linethi'ne jmr'ti'chla'rly in eox'rlh-iifiatirm With 'the novel field magnet Stfli'clzuif'e 6f the ihv'n tion. Ahother object at the invention is to provide a dynamo-eleeti'itb me eine having an ir'npho'w ed fier'l nie net gimme for field winainge in Whole 0i in ark bf the; neeel type described in my afore-mentlbii (1; teht. Other objecfi's 6f the ifiifefitibfi Ml be brought out in the course, (if 'the fclllohvihg d-e'sciipi-ton.

My efeeemeneiened Patent No. 1473;090

4e ensue the emeeuie Winding re fem ewe- "pole piece, Wherelfig'fire l is a diagrammatic end view, Fatty in Section, f foil): pole dynamoelectrijc hieehiii'e effibod i g my preeent inventioh; Fig.2 is a die" 51111 of the electricll c niieetiofis the wih in s of the m'achilu': efi ig, and Fig. 3 is ex memor diemm illhetrating the flux dIStI'ibiflZlOh re- 's l llting from the distributed end eondentret'ed exciting wih clin'g's 0f the machine bf he field mit'giie't of my improved (1 hime-felechflc m chin'e comprises a circular ma 1etic frame 5 to which ere slllitehly seclfli'ed lehiiheted ni'l" netic Dole pieces 6 each 01 Whi e has a siotted nner perilihery. Prefei'ab' y, the magnetic frame 5 is a solid steel fifig, and is m'olliitedpl e sm'hable base or pedestal 7 in My b'dnx 'ehi'el'lt mihn'er. In life drewihgs "I have shewn blts 8 for seeqi'i'ng the pele pieces 6 to the lpwgnetic frame 5. T "'e 9 on the inner peri hery of we pale pieee e 6 are eveniy clifstri need em are designed to clii'lf'y a distributed enmpeneslt'ihg w riding 10 a dietributed exciting winding 11. The di'tribiited cOm j'aekleating exeitin' windin 's ere preferslbfiy bf the tg'pe ueecribed hi 3 afdreineheiene'd eeee 5 that is we say, eeeh windin' is eompnee i of nifom ev rl'eppih cdils of eubetemian per em. pieeh inserleni eii ed tlieit the tiv'o windiflffs ferhi meeheflieeliy a single twd leyee a" vviP jdin-g.

A eeneemratea exciting Wind iii; 12 has een er epdei flleeeef eurreuhamg the wee e2: eeelg at the pale {flexes '6. The gale e wieh weir eeeeeaeee wifiai lg e dzfls 12) thee reeegfible the fil'd m' ee ehmiifitjdfi in Hireet eifwrent mechi "6f the bdlint p'ele' ebmnlmeeihg gem is 6 eriitl ends es @118 we galleries! and are secured to the magnetic frame .3 by bolts 8. Each pole piece 6 is of sufficient depth to accommodate the surrounding (oil of the concentrated exciting winding about the base of the pole piece. The pole pieces are, accordingly, preferably pro- \ldtitl with a shoulder 14 at each end which projects over a portion of the surrounding (Oil of the concentratml exciting Winding. In assembling, the coil of the concentrated exciting winding is first mounted on the base of the pole piece and the pole piece and coil are then secured to the steel frame 5 by the bolts 8. Each coil of the concentrated winding is thus firmly held between the frame 5 and the shoulders 14 of its associated pole piece.

The arcual widths of the pole pieces 6 and of the eoi'nmutating poles 13 are such that a suitable space is provided between the same for the accommodation of the coils of the concentrated exciting winding. This space is also of such width as to form in cf feet a double width slot between each end of each pole piece and the adjacent connnu tating pole. The bottoms of these double slots are occupied by the conductors of the concentrated exciting winding coils. The top portion of the double slots coiiperate with the distributed slots of the pole pieces to form substantially uniformly distributed slots over the entire inner periphery of the hold magnet of the machine, and the distributed compensating and exciting windings 10 and 11 are assembled in such substantially uniformly distributed slots. The double slots on each side of the commutating poles 13 may be closed by non-magnetic wedges, while the slots in the pole pieces may be closed by magnetic wedges in ac cordance with the principles described in my aforementioned patent.

The electrical connections of the windings of my improved dynamo-electric machine are indicated in the diagram of Fig. 2. The compensating winding 10 is connected in se ries with the commutated armature winding A. The distributed exciting winding 11 and the concentrated exciting winding 12 are represented as shunt connected windings. and are preferably connected in series with one another so as to enable the use of fine wire conductors for both exciting windings. It will of course be understood that either or both of the two exciting windings may, if desired, contain series coils or turns.

he flux distribution over one pole are produced by the combined distributed and concentrated exciting windings of my present machine is diagrammatically represented in Fi 3 of the drawings. The shaded rectangufar area 0 represents the flux due to the concentrated exciting winding 12, while the cross hatched pyramidal area d represents the flux dueto the distributed excitlug winding l1. The total exciting flux of the machine is obviously the sum of these two fluxes and the resultant flux distribution over one pole arc of the machine is represented by the combined areas cand (l. The flux form is thus of a more nearly rectangular shape than in a machine having only the distributed exciting winding, and hence more llux can be got through the machine.

In machines of the type described in my lLfOlGlllEllldOllGd patent it frequently happens that the coils of the exciting winding are of larger cross-sectional size than the coils of the compensating winding. Obviously, these two windings can behest assembled as a mechanically single two-layer lap winding when the coils of both windings are of the same size. By the use of my present invention the coils of the distributed exciting winding can be made exactly the same size as the coils of the compensating winding, and the additional excitation required for the machine can then be ob tained by th concentrated exciting winding.

The arrangement of the field windings in accordance with my present invention re sults in a most economical and efiicient utilization of the materials, and in addition provides a cheap, rugged construction possess ing excellent electrical characteristics. By sectionalizing the slotted portion of the field magnet, the exciting flux is forced to flow through the circular steel frame, and, due to the well known magnetic properties of steel, sudden variations in the exciting flux are thereby prevented. This is of particu lar advantage in motors Whose exciting field is frequently altered in magnitude or re versed, since it prevents a too sudden change in the exciting flux with the resultant likeli hood of disastrous flash-overs and similar difliculties.

What I claim as new and desire to secure by Letters Patent of the United States, is z- 1. A direct current dynamo-electric machine comprising a field magnet having a plurality of distributed slots on its inner periphery, a distributed exciting winding and a distributed compensating winding carried in said slots, said exciting winding and said compensating winding each being composed of substantially uniform coils interleaved so that the two windings form mechanically a single two-la er la winding, and a concentrated exciting winding associated with said field magnet and adapted to cooperate with said distributed exciti winding to produce the exciting field of said machine.

2. A direct current dynamo-electric ma chine comprising a magnetic frame, a lurality of laminated po e pieces secure to said frame, each of said ('lpole pieces having a plurality of distribute slots on its inner peit'lipher a distributed exciting winding an a istribuhed compensating windingrlm carried in said slots, said exciting winding and said compensating winding each being composed of substantially uniform coils interleaved to form mechanically a single two-layer lap winding, and a concentrated exciting winding surrounding said pole pieces and adapted to cooperate with said distributed exciting winding to produce the exciting field of said machine.

3. A direct current dynamo-electric machine comprising a magnetic frame, a plurality of laminated pole pieces secured to said frame, each of said pole pieces having a plurality of distributed slots on its inner periphery, commutating poles positioned between and spaced from said pole pieces, the space between each end of each pole piece and the adjacent commutating pole forming a double slot cooperating with the slots of said pole pieces to form substantially uniformly distributed slots over the entire inner periphery of the field magnet of the machine, and a distributed exciting Winding and a distributed compensated winding carried in said substantially uniformly distributed slots.

4. A direct current dynamo-electric machine comprising a magnetic frame, a plurality of laminated pole pieces secured to said frame, each of said pole pieces having a plurality of distributed slots on its inner periphery. commutating poles positioned between and spaced from said pole pieces, the space between each end of each pole piece and the adjacent commutating pole forming a double slot cooperating with the slots of said pole pieces to form substantially uniform distributed slots over the entire inner periphery of the field magnet of the machine, a distributed exciting winding carried in said slots, and a concentrated exciting winding surrounding said pole pieces and adapted to cooperate with said distributed exciting winding to produce the exciting field of said machine.

5. A direct current dynamo-electric machine comprising a magnetic frame, a lurality of laminated pole pieces secure to said frame, each of said pole pieces having a plurality of distributed slots on its inner periphery, commutating poles positioned between and spaced from said pole pieces, the

space between each end of each pole piece and the adjacent commutating pole forming a double slot cooperating with the slots of said pole pieces to form substantially uniformly distributed slots over the entire inner periphery of the field magnet of the machine, a distributed exciting winding and a distributed compensating winding carried in said substantially uniformly distributed slots, said exciting winding and said compensating winding each being composed of substantially uniform coils interleaved so that the two windings form mechanically a single two-layer lap winding, and a concentrated exciting winding composed of coils surrounding said pole pieces and adapted to coiiperate with said distributed exciting winding to produce the exciting field of said machine.

6. A direct current dynamo-electric machine having a field magnet comprising a circular steel frame, a plurality of laminated pole pieces secured to said frame, each of said pole pieces having a plurality of distributed slots on its inner periphery, and commutating poles positioned between and spaced from said pole pieces, and se cured to said frame, the space between each end of each pole piece and the adjacent commutating pole forming a double slot cooperating with the slots of said pole pieces to form substantially uniformly distributed slots over the entire inner periphery of the field magnet.

7. A direct current dynamoelectric machine having a field magnet comprising a magnetic frame, a plurality of magnetic pole pieces secured to said frame, each of said pole pieces having a plurality of distributed slots on its inner periphery, and commutating poles of magnetic material positioned between and spaced from said pole pieces and secured to said frame, the space between each end of each pole piece and the adjacent commutating pole forming a double slot cotiperating with the slots of said pole pieces to form substantially uniformly distributed slots over the entire inner periphery of the field magnet.

In witness whereof, I have hereunto set my hand this 11th day of May, 1916.

SVEN R. BERGMAN.

Copies of thin patent may be obtained for five centl each, by addressing the Commissioner of Patents, Washington, D. 0. 

